Radio waves may find exomoons

In renewed hope of finding life outside our solar system, physicists say that following a trail of radio wave emissions may lead them to discover exomoons harbouring life.

Scientists have in recent years discovered over 1,800 planets outside our solar system, or exoplanets, but so far, no one has been able to confirm an exomoon.

Physicists describe radio wave emissions that result from the interaction between Jupiter's magnetic field and its moon "Io".

By using detailed calculations about the Jupiter/Io dynamic to look for radio emissions, it may be possible to find moons orbiting an exoplanet.

"What if this mechanism happens outside of our solar system? We did the calculations and they show that actually there are some star systems that if they have moons, it could be discovered in this way," said Zdzislaw Musielak, a professor of physics from University of Texas at Arlington.

It is important to note when modelling the "Io" example to other planet/moon pairs that other moons do not necessarily need volcanic activity like that of "Io" to have an ionosphere.

"Larger moons such as Saturn's largest moon Titan can sustain a thick atmosphere and that could also mean they have an ionosphere. So volcanic activity is not a requirement," said lead author Joaquin Noyola.

The paper also addressed Alfven waves that are produced by the "Io" and Jupiter magnetosphere interaction, saying those waves could also be used to spot exomoons in similar situations.

Alfven waves are the rippling of the plasma in a magnetic field, first described by Hannes Alfven in the early 1940s.

The team has even talked about two exoplanets where they are "cautiously optimistic" that the observational community could apply the study's calculations to search for exomoons the size of our moon with future.